By David Borenstein, MD, Managing Editor theSpineCommunity.com
Ankylosing spondylitis (AS) is a form of progressive arthritis due to chronic inflammation of the spine and sacroiliac joints. Long-term inflammation can lead to calcification that may cause the spine to fuse anywhere from the sacroiliac joints to the neck, and in some cases fusion can affect the rib cage, resulting in restricted lung capacity and function. The goal of therapy for this disease is to stop inflammation and the subsequent calcification.
In the past, nonsteroidal anti-inflammatories (NSAIDs) such as aspirin, ibuprofen, and naproxen, were the only class of agent available for therapy of AS. NSAIDs were helpful in decreasing the pain and stiffness associated with AS but did not stop the progression of disease. For the last decade and a half, Tumor Necrosis Factor inhibitors (TFNi) have additionally been used for the management of AS. This type of inhibitor is a chemical signal (cytokine) produced by immune cells in AS, that mediate the disease-associated inflammation. These drugs have been effective with improvements of pain, functional ability, and inflammation. However, TNF therapies are not indicated for all AS patients.
In a prospective longitudinal study, a group of 511 were examined to determine if TNFi alone or TNFi plus NSAID would result in a decrease of new bone formation. At entry into the study, 30% were on both class of drugs, 27% on TNFi alone, 33% on NSAID alone, and 10 % on neither. The study groups were followed from two to six years. AS patients treated with TNFi had a decrease in new bone formation compared with progression expected with untreated AS. However, those treated with TFNi and NSAIDs had the least new bone formation.
The authors of this abstract made a specific point to caution against automatically placing AS patients on both classes of drugs, being careful to only direct therapy based on the level of inflammation associated with the patient’s disease. Some patients only need either an NSAID or a TNFi to control inflammation. If the complimentary drug is added to a single therapy, it should be added only when the current therapy is failing to control the progression of the disease.
Reference: Gensler L, Reveille JD, Ward M, et al. NSAIDs Modify the Effect of Tumor Necrosis Factor Inhibitors on New Bone Formation in Ankylosing Spondylitis. Ann Rheum Dis2016;75(Suppl2): 805